<?php

namespace Kiri\Server\Abstracts;

use Kiri\Di\Inject\Container;
use Kiri\Error\StdoutLogger;
use Kiri\Events\EventProvider;
use Kiri\Router\Router;
use Kiri\Server\Events\OnWorkerStart;
use Psr\Log\LoggerInterface;
use Swoole\Event;
use Swoole\Process;
use Kiri\Server\Processes\AbstractProcess;

class HotReload extends AbstractProcess
{


    /**
     * @var mixed
     */
    protected mixed $pipe;


    /**
     * @var LoggerInterface|StdoutLogger
     */
    #[Container(LoggerInterface::class)]
    public StdoutLogger|LoggerInterface $logger;


    /**
     * @var bool
     */
    protected bool $enable_coroutine = false;


    /**
     * @var array
     */
    protected array $watches = [];


    /**
     * @var bool
     */
    protected bool $enable_queue = false;


    /**
     * @var bool
     */
    protected bool $reloading = false;


    /**
     * @throws \Exception
     */
    public function __construct()
    {
        di(EventProvider::class)->on(OnWorkerStart::class, [di(Router::class), 'scan_build_route']);
    }


    /**
     * @return string
     */
    public function getName(): string
    {
        return 'hotReload';
    }


    /**
     * @return void
     */
    public function onSigterm(): void
    {
        // TODO: Implement onSigterm() method.
        $this->stop();
    }

    /**
     * @param ?Process $process
     */
    public function process(Process|null $process): void
    {
        $this->pipe = inotify_init();
        $this->addListen();
        Event::add($this->pipe, function () use ($process) {
            $read = inotify_read($this->pipe);
            if (count($read) > 0) {
                $this->reload();
            }
        });
        Event::cycle(function (): void {
            if ($this->isStop()) {
                Event::exit();
            }
        });
        Event::wait();
    }


    /**
     * @return void
     */
    public function reload(): void
    {
        if ($this->reloading) {
            return;
        }
        $this->reloading = true;

        di(StdoutLogger::class)->println('reloading server[' . \config('site.id', 'system-service') . '], please waite.');

        $this->clear();
        if (!$this->reloadWorkers()) {
            di(StdoutLogger::class)->println('reload server failed: master pid not found or signal failed');
        }
        $this->addListen();

        $this->reloading = false;
    }


    /**
     * @return void
     */
    private function reloadWorkers(): bool
    {
        $pid = $this->getMasterPid();
        if ($pid === null) {
            return false;
        }

        return Process::kill($pid, SIGUSR1);
    }

    private function getMasterPid(): ?int
    {
        $processes = $this->listProcesses();
        $candidates = [];

        $pidFile = function_exists('storage') ? storage('.swoole.pid') : '';
        if (is_file($pidFile)) {
            $candidates[] = (int)trim((string)file_get_contents($pidFile));
        }

        foreach ($processes as $process) {
            if ($this->isMasterProcessCommand($process['command'])) {
                $candidates[] = (int)$process['pid'];
            }
        }

        foreach (array_values(array_unique(array_filter($candidates))) as $pid) {
            if ($this->isProcessAlive($pid) && $this->isMasterPid($pid, $processes)) {
                return $pid;
            }
        }

        return null;
    }

    private function isMasterPid(int $pid, array $processes): bool
    {
        foreach ($processes as $process) {
            if ((int)$process['pid'] === $pid) {
                return $this->isMasterProcessCommand($process['command']) && $this->isSameAppProcess($pid);
            }
        }

        return false;
    }

    private function isMasterProcessCommand(string $command): bool
    {
        $prefix = '[' . config('site.id', 'system-service') . '].Master[';
        return str_contains($command, $prefix);
    }

    private function isSameAppProcess(int $pid): bool
    {
        $cwd = @readlink('/proc/' . $pid . '/cwd');
        if ($cwd === false || $cwd === '') {
            return false;
        }

        return $this->normalizePath($cwd) === $this->normalizePath(APP_PATH);
    }

    private function normalizePath(string $path): string
    {
        $real = realpath($path) ?: $path;
        return rtrim(str_replace('\\', '/', $real), '/');
    }

    private function listProcesses(): array
    {
        $lines = [];
        exec('ps -eo pid=,ppid=,args=', $lines);

        $processes = [];
        foreach ($lines as $line) {
            $line = trim($line);
            if ($line === '') {
                continue;
            }

            $parts = preg_split('/\s+/', $line, 3);
            if (count($parts) < 3) {
                continue;
            }

            $processes[] = [
                'pid' => (int)$parts[0],
                'ppid' => (int)$parts[1],
                'command' => $parts[2],
            ];
        }

        return $processes;
    }

    private function isProcessAlive(int $pid): bool
    {
        return $pid > 1 && @Process::kill($pid, 0);
    }
    protected function addListen(): void
    {
        foreach (config('servers.reload.listen') as $value) {
            $this->readDirectory($value);
        }
    }


    /**
     * @return void
     */
    protected function clear(): void
    {
        $this->watches = [];
    }

    /**
     * @param string $directory
     * @return void
     */
    public function readFile(string $directory): void
    {
        if (str_ends_with($directory, '.php') === true) {
            inotify_add_watch($this->pipe, $directory, IN_MODIFY | IN_MOVE | IN_CREATE | IN_DELETE);
        }
    }


    /**
     * @param string $directory
     * @return void
     */
    public function readDirectory(string $directory): void
    {
        foreach (glob($directory . '/*') as $data) {
            if (is_dir($data)) {
                $this->readDirectory($data);
            } else {
                $this->readFile($data);
            }
        }
    }
}